As to E1{\displaystyle E_{1}} we remark that substituting (65) in (41) and taking into consideration (64) we find,

G=ϰT,Q=ϰ−gT{\displaystyle G=\varkappa T,\ Q=\varkappa {\sqrt {-g}}T}

(120)

From this we conclude that E1{\displaystyle E_{1}} is zero if there is no matter inside the surface σ{\displaystyle \sigma }. In order to determine E1{\displaystyle E_{1}} in the opposite case, we remember that G{\displaystyle G} is independent of the choice of coordinates. To calculate this quantity we may therefore use the value of T{\displaystyle T} indicated in § 56, which is sufficient to calculate E1{\displaystyle E_{1}} as far as the terms of the first order. We have therefore

G=ϰr2ϱ{\displaystyle G={\frac {\varkappa }{r^{2}}}\varrho }

and if, using further on rectangular coordinates, we take for −g{\displaystyle {\sqrt {-g}}} the normal value c{\displaystyle c},

Q=cϰr2ϱ{\displaystyle Q={\frac {c\varkappa }{r^{2}}}\varrho }

From this we find by substitution in (114) for the case of the closed surface a surrounding the sphere